Did you know protein supplementation can provide benefits for endurance training as well as strength training? A May 2021 study found that supplementation improved aerobic capacity by increasing peak oxygen uptake and peak workload power.
Stay up to date on important protein studies and the big picture of nutrition research with an Examine Membership — try free for 14 days!
How much protein do you need per day?
Your optimal daily protein intake depends on your weight, goal, and level of physical activity.
in grams per kilogram of body weight (g/kg)
A full presentation of the research is available in our optimal protein intake guide.
- Humayun MA, et al. Reevaluation of the protein requirement in young men with the indicator amino acid oxidation techniqueReevaluation of the protein requirement in young men with the indicator amino acid oxidation technique .Am J Clin Nutr. (2007)
- Rafii M, et al. Dietary Protein Requirement of Men >65 Years Old Determined by the Indicator Amino Acid Oxidation Technique Is Higher than the Current Estimated Average Requirement. J Nutr. (2016)
- Rafii M, et al. Dietary protein requirement of female adults >65 years determined by the indicator amino acid oxidation technique is higher than current recommendations. J Nutr. (2015)
- Tang M, et al. Assessment of protein requirement in octogenarian women with use of the indicator amino acid oxidation technique. Am J Clin Nutr. (2014)
- Young VR, Marchini JS. Mechanisms and nutritional significance of metabolic responses to altered intakes of protein and amino acids, with reference to nutritional adaptation in humans. Am J Clin Nutr. (1990)
- Elango R, et al. Evidence that protein requirements have been significantly underestimated. Curr Opin Clin Nutr Metab Care. (2010)
- Bray GA, et al. Effect of dietary protein content on weight gain, energy expenditure, and body composition during overeating: a randomized controlled trial. JAMA. (2012)
- Thomas DT, Erdman KA, Burke LM. American College of Sports Medicine Joint Position Statement. Nutrition and Athletic Performance. Med Sci Sports Exerc. (2016)
- Jäger R, et al. International Society of Sports Nutrition Position Stand: protein and exercise. J Int Soc Sports Nutr. (2017)
- Morton RW, et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. Br J Sports Med. (2018)
- Wooding DJ, et al. Increased Protein Requirements in Female Athletes after Variable-Intensity Exercise. Med Sci Sports Exerc. (2017)
- Bandegan A, et al. Indicator Amino Acid-Derived Estimate of Dietary Protein Requirement for Male Bodybuilders on a Nontraining Day Is Several-Fold Greater than the Current Recommended Dietary Allowance. J Nutr. (2017)
- Leaf A, Antonio J. The Effects of Overfeeding on Body Composition: The Role of Macronutrient Composition - A Narrative Review. Int J Exerc Sci. (2017)
- Antonio J, et al. A high protein diet (3.4 g/kg/d) combined with a heavy resistance training program improves body composition in healthy trained men and women--a follow-up investigation. J Int Soc Sports Nutr. (2015)
- Phillips SM, Van Loon LJ. Dietary protein for athletes: from requirements to optimum adaptation. J Sports Sci. (2011)
- Helms ER, et al. A systematic review of dietary protein during caloric restriction in resistance trained lean athletes: a case for higher intakes. Int J Sport Nutr Exerc Metab. (2014)
- Aragon AA, et al. International society of sports nutrition position stand: diets and body composition. J Int Soc Sports Nutr. (2017)
- Helms ER, Aragon AA, Fitschen PJ. Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation. J Int Soc Sports Nutr. (2014)
- Krieger JW, et al. Effects of variation in protein and carbohydrate intake on body mass and composition during energy restriction: a meta-regression 1. Am J Clin Nutr. (2006)
- Wycherley TP, et al. Effects of energy-restricted high-protein, low-fat compared with standard-protein, low-fat diets: a meta-analysis of randomized controlled trials. Am J Clin Nutr. (2012)
- Kim JE, et al. Effects of dietary protein intake on body composition changes after weight loss in older adults: a systematic review and meta-analysis. Nutr Rev. (2016)
- Mathus-Vliegen EM, Obesity Management Task Force of the European Association for the Study of Obesity. Prevalence, pathophysiology, health consequences and treatment options of obesity in the elderly: a guideline. Obes Facts. (2012)
- Jensen MD, et al. 2013 AHA/ACC/TOS guideline for the management of overweight and obesity in adults: a report of the American College of Cardiology/American Heart Association Task Force on Practice Obesity Society . J Am Coll Cardiol. (2014)
- Blüher M. Adipose tissue inflammation: a cause or consequence of obesity-related insulin resistance?. Clin Sci (Lond). (2016)
- Santesso N, et al. Effects of higher- versus lower-protein diets on health outcomes: a systematic review and meta-analysis. Eur J Clin Nutr. (2012)
- Institute of Medicine. 10 Protein and Amino Acids. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. (2005)
- Stephens TV, et al. Protein requirements of healthy pregnant women during early and late gestation are higher than current recommendations. J Nutr. (2015)
- Elango R, Ball RO. Protein and Amino Acid Requirements during Pregnancy. Adv Nutr. (2016)
- Imdad A, Bhutta ZA. Maternal nutrition and birth outcomes: effect of balanced protein-energy supplementation. Paediatr Perinat Epidemiol. (2012)
- Burd NA, Gorissen SH, van Loon LJ. Anabolic resistance of muscle protein synthesis with aging. Exerc Sport Sci Rev. (2013)
- Moore DR, et al. Protein ingestion to stimulate myofibrillar protein synthesis requires greater relative protein intakes in healthy older versus younger men. J Gerontol A Biol Sci Med Sci. (2015)
- Deutz NE, Wolfe RR. Is there a maximal anabolic response to protein intake with a meal?. Clin Nutr. (2013)
- Kim IY, et al. The anabolic response to a meal containing different amounts of protein is not limited by the maximal stimulation of protein synthesis in healthy young adults. Am J Physiol Endocrinol Metab. (2016)
- Nair KS, Halliday D, Griggs RC. Leucine incorporation into mixed skeletal muscle protein in humans. Am J Physiol. (1988)
- Schoenfeld BJ, Aragon AA. How much protein can the body use in a single meal for muscle-building? Implications for daily protein distribution. Journal of the International Society of Sports Nutrition. (2018)